Hydraulic roof supports



March 11, 1969 RBOWER 3,431,737

HYIJJRAULIC ROOF SUPPORTS File d Feb. 14, 1967 [nvenfor A ew/s Rainer?Bower Sheet 5 of 5 March 11, 1969 R. BOWER 3,431,737

HYDRAULI C ROOF SUPPORTS Filed Feb. 14, 1967 Sheet 2 of 5 FIGQ Lye/772;Zeal/ls l PoberfBower March 11, 1969 L. R. BOWER 3,431,737

HYDRAULIC ROOF SUPPORTS Filed Feb. 14, 1967 Sheet 3 of s FIG?! [r7venfor Lew/'5' Robefl Bo wer United States Patent Office 3,431,737Patented Mar. 11, 1969 4 Claims ABSTRACT OF THE DISCLOSURE An advancingmine roof support having a pair of hydraulic chocks joined by springsteel strips at floor and roof level, the strips bowed downwardly andupwardly respectively and held in the chocks by pins, some of the stripsextending beyond one of the chocks and connected by a plate to form asupport in advance of said one chock.

This invention relates to mine roof supports, and particularly thoughnot exclusively to mine roof supports for use in longwall working inthin seams and intended to be attached to a face conveyor. The inventionfinds particular application in underground coal mines, but can beapplied in any form of underground mineral mining where working methodsakin to those of coal mining are adopted.

It is one object of this invention to provide a mine roof supportadapted for low mine seams and one which is flexible and can adaptitself to irregularities in the mine floor or roof.

Another object is to provide a mine roof support of the self advancingtype with provisions to support the roof over the face conveyor inadvance of the forward chock.

According to the invention we provide a mine roof support comprising atleast two fluid operated chocks each of which has a roof canopy whoseunderside has a groove, the chocks being joined by a roof-contactingmember in the form of a strip of spring steel which is at least partlylocated in the groove.

In a preferred form of the invention, the strip of spring steel is solocated by means of one or more removable pins. These pins seat insuitable apertures in the roof canopy, or in suitable brackets or thelike secured thereto. The strip of spring steel may have a turned-overend through which an additional pin can pass to make the spring steelstrip captive to the canopy.

Further features of the invention will appear from the followingillustrative and particular description thereof given with reference tothe accompanying drawings, in which:

FIG. 1 is a side elevation of one form of roof support according to theinvention,

FIG. 2 is a plan view of the support shown in FIG. 1,

FIG. 3 is a side elevation of the support shown in FIG. 1 showingparticularly the arrangement and construction of the floor and rooflevel outer spring sets,

FIG. '4 shows the support shown in FIGS. 1 and 2 and particularly showsthe arrangement of the central springs at floor and roof level.

The illustrated mine roof support comprises a front hydraulic chock anda rear hydraulic chock 12, the former of which has a base 14 and a roofcanopy 16 and the latter of which has a base 18 and a roof canopy 20.Spring steel sets generally indicated at 22, 24 and 26- in FIG. 2 extendbetween these roof canopies and two pairs of spring steel strips, onepair generally indicate-d at 30 and the other pair at 50, extend betweenthe base members. The strips are located beneath springs 22 and 26 andthe springs 30 are spaced inwardly therefrom as seen in FIG. 2. In analternative embodiment, not illllllstrajted, the support could comprisethree chocks in line a ea An extension plate assembly 34 is mounted atthe forward end of cantilever springs 22, 26 and in use gives support tothe roof above the face conveyor.

As seen best in FIG. 3, the outer spring sets at roof level are eachmade up of three springs 32, 34 and 36, the upper two extending betweenthe front and rear roof canopies and beyond the front, and the thirdspring 36 being attached to the front roof canopy and serving as acantilever support. The outer pair of springs 50 at floor level extendsbetween pins 40, 42 one pin being mounted in a side wall 44 -(seeFIG. 1) on the front base member and one being removably mounted in aside wall 46 on the rear base member. These pins extend respectivelybetween outer side walls 44 and 46 and inner side walls (notreferenced).

The central springs are seen best in FIG. 4 and are located on orsymmetrical to the centreline of the support. They comprise one roofspring 24 and two floor springs 30 somewhat inset from the spring strips50-. Each spring 30 extend between pins 52 on the respective basemembers. The spring 24 extends between pins 53 on the respective roofcanopies. In common with the remaining springs (except 36) the springs24, 30 and 50 are preformed to a shape such that they present a convexsurface towards roof or floor extending beyond the plane of the uppersurface of the roof canopies 16, 20 or the plane of the lower surface ofthe base members 14, 18 as the case may be. The number and width of theupper and lower centre springs can be adjusted in order to suit varyingfloor and roof conditions.

The upper portions of the chocks 10 and 12 are formed in the shape of aflat cone having in the centre a raised portion which acts as acentralising and retaining boss for the roof canopies 16, 20, the shapeof the said portions and the design of the roof canopies being such asto allow the canopies a certain amount of universal pivotal movement.

As can be seen from FIG. 2, the undersides of the roof canopies havegrooves in which part of the spring steel strips are located, in thatthe canopies are provided with downwardly projecting plates or bracketswhich form the side walls of the grooves. Mechanical equivalents of sucha construction are deemed to be within the scope of the presentinvention.

The base members 14 and 18 have similar open grooves, however openingupwardly in this case, to receive the floor level springs 50.

In the preferred embodiment of this invention, it has been mentionedthat the roof level spring sets comprise three individual springs, theuppermost of which (32) has an eye formed at its rear extremity. Thesecond spring of this set, namely 34, also has an eye formed at its rearextremity, this eye being so sized that it can be received within theeye formed in spring 32. A removable pin 54 makes these two springscaptive to the roof member 20. The cantilever spring 36 is located by aneye formed at its rear end engaged by a removable pin 56, and thisspring and the springs 32 and 34 are all supported by a generallyhorizontal removable pin 58. In operation, a supporting pin 61 and thesupporting pin 58 form fulcrums when loading is applied to the archedportions of springs 32 and 34, as for instance upon setting of thechocks to the roof, and pin 58 forms a fulcrum point for all threesprings when the cantilever portions 34 is similarly deflected bycontact with the roof.

The outer springs at floor level (50) are positioned, as stated,directly below the outer spring sets 22 and 26 at roof level, and areformed with an eye at each end of a size appropriately chosen inrelation to removable pins 40, 42.

Referring to FIG. 2, on either side of the roof support are seen doubleacting hydraulic rams 60, 62 each of which is attached to an attachmentplate, 64, 66. These parts function to effect steering of the roofsupport dur ing forward movement.

The construction specifically described herein has the importantpractical advantages that the whole roof support is constructed ofsimple parts and is easily dismantled, for example for routinemaintenance, Replacement of roof or floor springs is particularly simpleas it is 1 merely necessary to withdraw the appropriate removable pin orpins.

I claim:

1. An advancing mine roof support comprising at least a forward and arearward fluid-operated chock each of which has a roof canopy whoseunderside has at least one groove, the chocks being joined by aplurality of roofcontacting members in the form of strips of springsteel, and by a plurality of floor-contacting members in the form ofstrips of spring steel, each of the laterally outermost roof contactingmembers bein at least partly located in a corresponding one of thegrooves, and the said outermost roof-contacting members projectingbeyond the forward chock and a plate supported on and extending betweenthem which in operation serves to provide support to the roof in advanceof the forward chock.

2. A support according to claim 1 in which each roof contacting strip ispreformed to a shape such that it presents a convex surface towards roofand extends beyond the plane of the upper surface of the roof canopiesand each floor contacting strip presents a convex surface toward thefloor and extends beyond the plane of the lower surface of the floorcontacting members.

3. A support according to claim 2 which includes four parallel strips atfloor level and three at roof level joining the chocks.

4. A support according to claim 1 in which the outermost strip-s at rooflevel each have a turned-over end in the form of a loop, a pin in saidcanopy and passing through said loop to render the said strip captive tothe canopy and in which a further pin is provided in said canopy tomaintain each said strip in its associated groove.

References Cited UNITED STATES PATENTS OTHER REFERENCES M24317, V1/5c,8-1956, German patent application to Muller et 211., 61-45.

JACOB SHAPIRO, Primary Examiner.

US. Cl. X.R. 248-357

